166 REPORT — 1861. 



perivisceral fluid — that also probably a nutritive fluid — lie has not attempted to 

 determine, 



On the Question whether the Hair is subject or not to a Sudden Change of Colour. 

 By John Dayt, M.D., F.R.S. #c. 



The conclusion arrived at by the author respecting^ this question is negative, partly 

 founded on defective liistorical evidence, none of the instances adduced of sudden 

 change, according to him, being of a satisfactory kind, and partly on physiological 

 data, the himian hair, after it has sprimg from the bidb, the gland which secretes it, 

 being " anorganic," destitute of any chculating fluid, and remarkable for its power 

 of resisting change when exposed to the action of chemical agents. 



The attempts made to support the popular notion that hair may suddenly, even 

 in a night or in a shorter space of time, become grey, by reference to change of 

 colom- of the coats of certain of the mammalia, and of the plumage of certain birds on 

 the approach of winter and of summer, are objected to on the ground that in all these 

 instances the change of colom* is, as far as he has been able to ascertain, associated 

 with a change of hair and feathers, that is, with a new growth, the old being shed. 



Observations on the Encephalon of Mammalia. By E.. Gaenek, F.L.S, 

 In this paper the author adverted to the extreme doubt stiU dwelling in the 

 minds of physicians and physiologists with respect to the fimctions of the different 

 parts of the brain. He took up the theoiy that the cerebellum is not the organ of 

 amativeness, as maintained by Gall, but the distributor of the motive impulse de- 

 scending fi-om the cerebrum. His proofs were derived from comparative anatomy, 

 and fi'om the development of the cerebellum at difl'erent ages, as well as from a re- 

 markable case of disease. He also endeavoured to localise the som-ces of its different 

 kinds of influences, whether they are exerted upon the head, trunk, or limbs, or 

 in flexion and extension. The cerebellum seems to be as often a separator as a 

 combiner of cerebral impidse ; for instance, the mofores ocvhrmn are given oft' above 

 the cerebellar connexion, and we have no power of separate action in these nerves, 

 whilst it is the reverse in both respects with the abducentes. With respect to 

 phi'enology, he obsei-ved that its list of facidties and feelings is very complete, whilst 

 one-half of the convolutions, their supposed seats, do not appear on the upper sur- 

 face of the brain at all, or influence the form of the skidl. He next endeavoured 

 to prove the functions of the component parts of the brain, and traced the develop- 

 ment of the convolutions fi-om the smooth brain of the rodentia to that of the ape 

 and man. The distinction and description of these folds is not without the pale of 

 anatomy, and thek consideration forms the transcendental plan of arranging the 

 Mammalia. He made a few observations on the general form of the cranium. 

 Females, he thinks, have by no means, comparatively speaking, low foreheads, but 

 the reverse, at least centrally ; their skull is also more lozenge-shaped, a little pro- 

 minent at the sides. He thinks men of low or moderate statm-e have commonly 

 an advantage in cerebral development ; but the convolutions in a small brain are 

 oftener richer or more numerous and tortiious in their divisions than in the other 

 case ; and some eminent men have had very small heads. With regard to the boat- 

 shaped or long-head skull, from before to behind, and the roimder and broader 

 form, the differences, sometimes perhaps national, maybe in others only individual; 

 the author thinks that the former variety has in some respects (the exact stiidies 

 for instance) veiy fi-equently the advantage. Twins have been noticed by the 

 author, one having the elongated head, the other the broad. In the case above 

 alluded to of cerebellar disease, it was a cyst without any other lesion of the 

 encephalon, and locomotion was greatly interfered with, imless the cerebmm was 

 brought into action ; the abducentes were pai'alysed, the motores not. The paper 

 was lUusti-ated with life-size photographs of brains of healthy persons of difl'erent 

 ages, of a woman of a hundred, of a deaf mute, and of idiots and epileptics. 



On certain points in the Anatomy and Physiology of the Dibranchiate Cepha- 

 lopoda. By Albany Hancock. 

 The authoj confines his obseiTations in this paper almost entirely to the so-called 



